Pyrazoles are synthesized by the reaction of α,β-unsaturated aldehydes with hydrazine and subsequent dehydrogenation. 37622-90-5, formula is C6H8N2O2, Name is Ethyl 4-pyrazolecarboxylate. Substituted pyrazoles are prepared by condensation of 1,3-diketones with hydrazine (Knorr-type reactions). For example, acetylacetone and hydrazine gives 3,5-dimethylpyrazole. Electric Literature of 37622-90-5.
Sun, Mingli;Zhou, Yuhui;Li, Laiqiang;Wang, Lei;Ma, Yongmin;Li, Pinhua research published 《 Electrochemically promoted C-3 amination of 2H-indazoles》, the research content is summarized as follows. A metal-free and external oxidant-free electrochem. method for the C-3 amination of 2H-indazoles was reported for the synthesis of indazolyl-amines I [R = n-Bu, 1-pyrazolyl, morpholino, etc.; R1 = H, 5-F, 6-Br, etc.; R2 = Ph, 1-naphthyl, 2-pyridyl, etc.]. The protocol employed com. available azoles and aliphatic amines as amination reagents and had a broad substrate scope, providing the corresponding C3-amination products in high yields at room temperature Mechanistic studies indicated that an oxidative addition/elimination sequence was involved under electrochem. conditions.
37622-90-5, Ethyl 4-pyrazolecarboxylate, also known as Ethyl pyrazole-4-carboxylate, is a useful research compound. Its molecular formula is C6H8N2O2 and its molecular weight is 140.14 g/mol. The purity is usually 95%.
Ethyl pyrazole-4-carboxylate is a low yield, transition metal salt that is used in the synthesis of pyrazoles. It can be synthesized by the reaction of sodium ethoxide with ethyl chloroformate and a Grignard reagent. Sodium ethoxide is added to a suspension of sodium chloride and dried ethyl chloroformate, followed by addition of magnesium turnings. The mixture is refluxed for one hour, cooled, and filtered to give crystals. Ethyl pyrazole-4-carboxylate is used in the preparation of ethyl esters from aliphatic alcohols by reacting with boron trichloride or phosphorus pentachloride. It participates in certain chemical reactions as a byproduct and can damage equipment during chemical reactions. The yield of this compound can be increased by using an excess amount of Grignard reagent or adding hexamethylenetetramine to the reaction mixture, Electric Literature of 37622-90-5
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics